Achates rolls out nation's first CARB 2027 diesel truck to Walmart

Updated Apr 29, 2022
Achates Power opposed-piston engine Walmart
A heavy-duty, opposed-piston engine from Achates Power shown in this Peterbilt 579 and delivered to Walmart is the nation's first diesel engine to meet CARB's 2027 emissions standards.
Achates Power

San Diego-based Achates Power announced today that the heavy-duty, opposed-piston engine it developed in a project funded by the California Air Resources Board (CARB) and several partners entered fleet service with Walmart Corporation in a Peterbilt 579 tractor.

It is the only diesel engine operating on the road capable of meeting CARB’s 2027 regulation, according to Achates, which requires a 90% reduction in emissions of nitrogen oxide (NOx) compared to current standards. 

The project team also demonstrated that the two-stroke engine reduces carbon dioxide (CO2) by 10%. The Achates Power ultra-low-NOx engine is engineered to achieve superior fuel efficiency because of its lower heat losses, improved combustion and reduced pumping losses.

[Related: Achates CEO explains why their near-zero diesel may not be produced]

The cleaner engine is able to deliver ultra-low NOx by managing exhaust gas temperatures to ensure rapid catalyst light off and by maintaining aftertreatment temperatures at optimum operating conditions in all driving conditions. 

CALSTART leads the extensive demonstration project team. The team includes Aramco Americas, BASF, Corning, Southwest Research Institute, Borg Warner, Eaton, Faurecia, Tenneco, Eberspaecher and SuperTurbo.

“Achates Power is grateful that the California Air Resources Board led the funding of this demonstration program, and we are pleased to work with our partners around the world to bring opposed-piston engines to the market,” said Dave Crompton, president and CEO of Achates Power. “It is particularly noteworthy that we were able to achieve the extremely stringent state NOx limits without any additional emissions control devices, reducing cost, complexity, and compliance risk of ultralow NOx powertrain solutions.” 

In addition to CARB, the South Coast Air Quality Management District, San Joaquin Valley Air Pollution Control District, and the Sacramento Metro Air Quality Management District provided funding for the project. 

“Reducing emissions from heavy-duty vehicles is critically needed to clean the air,” said Wayne Nastri, Executive Officer of the South Coast Air Quality Management District. “This type of innovative, cleaner engine design is what we need not only here locally in the South Coast, but across the country to protect communities nationwide suffering from pollution associated with goods movement.” 

Achates reports that the opposed-piston engine can use existing manufacturing facilities, processes, and materials to allow rapid time-to-market and deployment. It also uses existing components and supply chains. It is expected to cost less than current engines, even as it meets much more stringent environmental regulations. It does not require any additional emissions control devices and has a reduced part count compared to conventional engines. In addition, Achates Power is conducting further testing with a fully aged catalyst (the equivalent of 800,000 miles of operation) to demonstrate continued ability to meet CARB’s stringent standards. 

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